There is one body and one Spirit, just as you were called to the one hope of your calling, one Lord, one faith, one baptism, one God and Father of all, who is above all and through all and in all.
Ephesians 4:4-6

Why can't we all just get along? That question doesn't just express a vague wish; Paul directs us to be in union with other Christians. This is true even if we do not agree on major points of doctrine, for example, baptism. There is only one baptism, even if our sisters & brothers in Christ do not see it our way -- or we theirs.

Why do we resist & reject union? Pride, fear, fear of loss of power, prejudice -- and other similar emotions, none of which is acceptable to Jesus.

+ pax